Problem: You are trying to set up different regions on your site using WPML, each represented by a language. You want the URL language code for the USA to be /us/ instead of the default /en-us/. However, when attempting to create a custom language for the US, you encounter errors indicating that 'The default locale already exists.' and 'The hreflang already exists.' Solution: The issue arises because the values when adding a custom language need to be unique and cannot be reused across multiple languages. Here’s how you can resolve this: 1. Navigate to WPML -> Languages -> Add languages and add the English language. 2. Go to Edit languages. 3. Change the default locale and hreflang to something unique and save the changes. 4. Now, add your custom language and assign it en_US and en-us. You can see a setup example here: WPML->Languages->Edit languages.
If this solution does not apply to your case, or if it seems outdated, we recommend checking the related known issues, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. Should you need further assistance, please open a new support ticket.
